When I played with Lee Konitz a little bit, he would start always start with "Solar." Afterwards he would say, "That was not by Miles Davis, but by Chuck Wayne." I was unsurprised to hear this, because many years ago Jim McNeely had told his jazz camp students the same thing, with the caveat that Miles had changed the first chord from major to minor.

Well, they were both right. Larry Appelbaum has found proof. Read and listen here.  

There's been a lot of internet and forum discussion. I particularly like Marc Myers's take, especially since he doesn't shy away from race. 

Just a few more thoughts: 

I think the unusual minor is why it became a popular jam session staple.  It certainly made the original 1954 recording distinctive: Miles Davis over a minor chord, that's a canonical sound. Now that we know it is Wayne's tune, are we going to honor the composer and change the first chord to major again? (Not me, anyway.)  

Miles doesn't play the tune very clearly. It's an impressionistic take at the begining and even more abstracted at the end. That's how Bill Evans and Lee Konitz play it too. After all, the melody is mostly just descending guide tones over a distinctive progression: "How High the Moon" meets the blues. The jazz-school approach of several horns reading out the Real Book version in unison is comparatively banal. 

Several tracks on early Davis dates for Prestige are quick but soulful looks at interesting blues progressions. Since the outlines of "Solar" are so hazy, it's surprising that it became so popular with others…which is perhaps why he waited so long (1963)  to copyright it himself. At any rate, it never entered the band book, which is why the quote on Miles's gravestone is doubly ironic. (Thanks to Mark Stryker for showing me the photo.)

Finally, Lewis Porter pointed out to me that the way all musicians pronounce "Solar" (the tune) is weirdly different than "solar" (like "solar rays").

Strange history for a friendly little tune!